NOvA sees first antineutrino

On Feb. 20, the NOvA neutrino experiment observed its first antineutrino, only two hours after the Fermilab accelerator complex switched to antineutrino delivery mode. The NOvA collaboration saw the antineutrino in the experiment’s far detector, which is located in northern Minnesota.

NOvA scientists hope to learn more about how and why neutrinos change between one type and another. The three types, called flavors, are the muon, electron and tau neutrino. Over longer distances, neutrinos can flip between these flavors. NOvA is specifically designed to study muon neutrinos changing into electron neutrinos. Unraveling this mystery may help scientists understand why the universe is composed of matter and why that matter was not annihilated by antimatter after the Big Bang.

This plot shows the tracks of particles resulting from an antineutrino interaction inside the NOvA far detector. Image: NOvA collaboration